Improvement in steam-g-enehator smoke-stacks



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wILLIAIZIr HOLDCRAFT :AND DAVID IICLAUGHL PENNSYLVANIA.

Letters Patent No. 97,509, (lated December- 7, 1869;- antedatedv1irocember 20,1869

i IMPROVEMENT IN STEAM-GENERTDR SMOKE-STAGES.

The Schedule referred to in these Letters Patent and-making part ofthe same.

' To all whom 'it'finay concern Be it known that we, WILLIAM HOLDCRAFT and DAVID MCL'AUGHLIN of Philadelphia, in the county of Philadelphia, inthe State of Pennsylvania, have invented a newanduseful Mode of Creating an .A1-ticial Draught in a Smoke-Stack or.Chimney; and we do hereby declare that the following vis a full and eX- act description of the same, reference being had to the annexed drawings, and to the letters of reference marked thereon.

The nature of our invention consists in locating in the centre of a smoke-stack or chimney, above the lues, a metallic shell, the form of which is that of a truncated cone and semispherical cup combined.

From this shell seventeen`(17)A jets of steam issue, in such a manner as to completely expel the air from the interior-of` the smoke-stackerchimney, upon the same principle-that bodies are elevated by a natural whirlwind.

To enable othersskilled in the art to make and use our invention, we will proceed to describe itsconstruction and operation.l l Y Eigure 1 is a full-size drawing of the perforated shell,

through which steam issues Ainto the smoke-stack or Figure 2 is a' topv or birds-eye view ofthe same. Figure 3 is a View commencingat the semispherical line D, and looking toward the apex of the cone.

' Similar figures and letters refer to like points in the several views.

` 4, The size ofthe shell here shown is' intended for an eighteensinch stack or chimney, ,and is designed to be attached to the upper -end= of a vertical steam-pipe, three-fourths of an inch in diameter, the pipe being connected with the boiler.

Fig. 1, therefore, representsjthe shell E in its ,working position.

Steam enters the shell E at F, and as the-arca of the 4tln'ee-tourtb-inch pipeis about tive times greater than-th'ecombined areas ofthe seventeen holes through the shell, the pressureof steam in the shell will be the same asthat in the boiler. rlhe sixteen holes in the shell E, onesxteenth of an inch in diameter, are

drilled as follows, viz:

The four holes on line D, onanA angle of forty-iive degrees. v j

he four holes on line G, on an angle of sixty degrecs.

The four holes online B, on an angle of seventy-two' f degrees. 4

The four holes ou line A, on an angle of eighty-three degrees. p

In addition to the angles above described, all of the holes on the lines A B O D are drilled tangential to circles on which they are started, as shown by the arrows in iig. 3,'the angles being ten degrees from the radial lines, at their intersection with the several circles on which the holes are located. y

A rlhe hoiein the apex of the cone is one-eighth of an inch in diameter, and is drilled on a line with the oentreof the cone, inrelation to the centre of the shell F.

The other holes are located on spiral lines, as ir'idicated by the figs. l, 2, 3, 4, on the lines A B C D, in fig. 1.

rlhe particular form of the shell, together with the radiating angles, on which the jets of steam issue therefrom, causes the air inthe stack or chimney to be expelled by a `less volume of' steam than byany u the centre of the stack or chimney, which action takes place at the height of six feetabove the shell.

What we claim as our invention, and desire to secure by Letters Patent, is y The construction and arrangement of the shell' E, in the manner and for the purpose herein set forth.

WILLIAM HQLDCRAFT. DAVID MCLAUGHLIN.

Witnesseszl Jos. G. TITTERNIARY, ELIAS THoMAs.

IN, or PHILADELPHIA, 

